In theory if the two pools were hacked and the hackers executed an attack on the blockchain then the confidence in bitcoin could be eroded to the amount that bitcoin price would crash.

In reality this will not happen as when evidence of an actual attack against the network by specific pool(s) miners would pretty much instantly pull their hashpower from those pools to prevent the attacks from continuing. IMO the very large miners with significant amounts of money invested in miners would likely be monitoring a number of sources (forums, MSM, the blockchain) for potential evidence of an attack on the network by the pool they are mining on and would react accordingly